Global trade exchange is like swapping toys with other kids at school. You have a toy that another kid wants, and they have a toy that you want. So you make a deal to exchange toys. Similarly, countries around the world have things that they make or grow, such as clothes or food, and other countries want these things. So they make deals to trade goods with each other.
Just like you might have to give more toys in exchange for a really cool toy, countries have to give something valuable to get the goods they want from another country. This could be money, other goods, or even something like helping with a big project. Sometimes, countries have to communicate a lot to make sure the trade deal is fair for both sides, just like you and the other kid might need to talk about which toys you each want to make sure you're both happy with the trade.
Global trade exchange helps countries work together to get the things they need and want, and it helps all of us have access to a wider variety of goods and services.